From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E28C79C9 for ; Thu, 12 Jan 2023 14:31:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA3F3C433D2; Thu, 12 Jan 2023 14:31:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673533914; bh=AvXULct0/JkCv208GZNXEeBmUO18IY6RwhNjgt/+M38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pKXkGdemFvDY1fSbFPWEcyajSRdbicwN8qnHsSZvwESNtF4RtqBvUHrXwdYJrfAIp BtrzGtudCQOoUfIgbgPMnJVyeJaKap5IDIb1qPiP/omO3TT1nwUu7BEH1Nn/OZu+9b 6jDk/oDsw+ZNi6CnQJlx58AzFq46H31kFs9Vksww= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dima Chumak , Vlad Buslov , Saeed Mahameed , Nikita Zhandarovich Subject: [PATCH 5.10 603/783] net/mlx5e: Fix nullptr in mlx5e_tc_add_fdb_flow() Date: Thu, 12 Jan 2023 14:55:19 +0100 Message-Id: <20230112135552.228133387@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dima Chumak commit fe7738eb3ca3631a75844e790f6cb576c0fe7b00 upstream. The result of __dev_get_by_index() is not checked for NULL, which then passed to mlx5e_attach_encap() and gets dereferenced. Also, in case of a successful lookup, the net_device reference count is not incremented, which may result in net_device pointer becoming invalid at any time during mlx5e_attach_encap() execution. Fix by using dev_get_by_index(), which does proper reference counting on the net_device pointer. Also, handle nullptr return value when mirred device is not found. It's safe to call dev_put() on the mirred net_device pointer, right after mlx5e_attach_encap() call, because it's not being saved/copied down the call chain. Fixes: 3c37745ec614 ("net/mlx5e: Properly deal with encap flows add/del under neigh update") Addresses-Coverity: ("Dereference null return value") Signed-off-by: Dima Chumak Reviewed-by: Vlad Buslov Signed-off-by: Saeed Mahameed Signed-off-by: Nikita Zhandarovich Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -1344,9 +1344,9 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv struct netlink_ext_ack *extack) { struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; - struct net_device *out_dev, *encap_dev = NULL; struct mlx5e_tc_flow_parse_attr *parse_attr; struct mlx5_flow_attr *attr = flow->attr; + struct net_device *encap_dev = NULL; struct mlx5_esw_flow_attr *esw_attr; struct mlx5_fc *counter = NULL; struct mlx5e_rep_priv *rpriv; @@ -1391,16 +1391,22 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv esw_attr = attr->esw_attr; for (out_index = 0; out_index < MLX5_MAX_FLOW_FWD_VPORTS; out_index++) { + struct net_device *out_dev; int mirred_ifindex; if (!(esw_attr->dests[out_index].flags & MLX5_ESW_DEST_ENCAP)) continue; mirred_ifindex = parse_attr->mirred_ifindex[out_index]; - out_dev = __dev_get_by_index(dev_net(priv->netdev), - mirred_ifindex); + out_dev = dev_get_by_index(dev_net(priv->netdev), mirred_ifindex); + if (!out_dev) { + NL_SET_ERR_MSG_MOD(extack, "Requested mirred device not found"); + err = -ENODEV; + return err; + } err = mlx5e_attach_encap(priv, flow, out_dev, out_index, extack, &encap_dev, &encap_valid); + dev_put(out_dev); if (err) return err;